1. Field of the Invention
This invention relates, generally, to highly efficient air conditioning systems for data centers. More particularly, it relates to a system that includes a liquid overfeed air conditioning unit that supplies conditioned air to the data center at temperatures of forty-five degrees Fahrenheit and below.
2. Description of the Prior Art
Data centers are buildings that house large numbers of file servers, data processors, or other heat-generating computer components. Typically, the interior of a data center is filled with multiple rows of cabinet-like equipment called racks that are arranged in parallel relation to one another throughout the entire extent of the data center. An aisle for service personnel is provided between each row of racks and at each end of the building. Each rack houses multiple, vertically spaced components. In this way, a very large number of file servers or other components can be placed in a data center.
The heat collectively generated by very large numbers of densely packed components within a data center is sufficient to cause catastrophic failure of the file servers. Accordingly, even the earliest data centers were air conditioned twenty four hours per day, every day of the year. These early data centers utilized common window units, but these proved inadequate as computer componentd evolved and consumed higher levels of energy, thereby creating more heat.
Modern data centers employ packaged chilled water or direct expansion (DX) air conditioning units positioned inside the data center. Such units represent a substantial improvement over window units but they have a number of drawbacks. For example, they are placed inside the data center and thus reduce the number of racks that can be housed therein. Moreover, they cool the supply air to about fifty five degrees. This type of cooling was acceptable before components were packed as densely as they are today. Many densely populated data centers throughout the world have components that are now operating under thermal stress, or very near their highest acceptable operating temperatures. As data centers are being converted or renovated to house as many components as possible at the greatest possible density, it is clear that a revolutionary new way of cooling data centers is required.
However, even though the data center industry is alarmed over the current situation, and has been for several years, no one has come forward with a solution to the problem.
Accordingly, it may be concluded that the solution to the problem was not obvious to those of ordinary skill in the data center field at the time the present invention was made.
The longstanding but heretofore unfulfilled need for an improved apparatus and method for cooling data centers is now met by a new, useful, and nonobvious apparatus for cooling a data center of the type including a plurality of rows of computer racks. The invention includes at least one liquid overfeed air conditioning unit disposed externally to the data center. Each row of computer racks has an aisle on its opposite sides so that data center personnel may walk between the rows. At least one conditioned air supply register is disposed in at least one of the aisles and at least one air conditioning duct provides fluid communication between the heat exchanger outlet of the liquid overfeed air conditioning unit and said at least one register.
In this way, supply air at a temperature of forty-five degrees Fahrenheit or lower is supplied to the interior of the data center by the liquid overfeed air conditioning unit and its associated distribution ducts. Moreover, the flow rate of supply air into the interior of the data center is reduced relative to a flow rate of supply air produced by a chilled water or a direct expansion air conditioning unit due to the increased work capacity of the lower temperature air. Noise reduction within the interior of said data center is therefore achieved and electrical energy is conserved because the liquid overfeed air conditioning system requires less energy relative to a chilled water or a direct expansion air conditioning system.
Each of the computer racks includes a plurality of vertically spaced apart components. The racks are open on their front and back so that conditioned air can flow therethrough from one aisle to another. Circulation fans are mounted so that supply air is drawn into cooling relation to each component through the substantially open front of the rack, flows past the heat-generating equipment, acquiring heat therefrom, and into the aisle adjacent the back of the rack.
The primary object of this invention is to provide an enhanced means for cooling computer components housed in a data center.
A closely related object is to provide efficient means for producing and delivering conditioned supply air to the interior of a data center having a temperature of forty-five degrees Fahrenheit and below.
A more specific object is to cool components housed in a data center with a liquid overfeed air conditioning system.
Additional important objects are to conserve data center floor space, electrical energy and attenuate noise by reducing the flow rate of supply air into a data center, said reduced flow rate being made possible by the reduced temperature of supply air provided by the liquid overfeed air conditioning unit relative to the temperature of supply air provided by chilled water and direct expansion air conditioning units.
Yet another object is to reduce the chances that computer equipment within the data center will be exposed to condensation or frost.
These and other important objects, advantages, and features of the invention will become clear as this description proceeds.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter and the scope of the invention will be indicated in the claims.